By default Quake uses a FOV (field of view) of 90. You can set a higher FOV to distort your view to see more to the sides of the screen. Setting a higher FOV also means that the center of the screen will be "zoomed away".

If you are using a widescreen resolution to play Quake and keep the FOV of 90, you will actually play with a zoomed-in view instead of a realistic one. Widescreen means you should be able to see the same stuff like before but with additional space on the sides.

Lordhavoc was so nice to share the formula:

atan(tan(120*pi/360)*0.75*resolution_x/resolution_y)*360/pi

For your convenience, here is a table of some more or less common resolutions and the resulting FOV values.

• 5:4 (1.250) resolutions are 1280x1024 and 2560x2048
• 4:3 (1.3333) resolutions are 320x240, 640x480, 768x576, 800x600, 1024x768, 1280x960, 1400x1050, 1600x1200, 2048x1536. For these you do not need to adjust the FOV.
• 3:2 (1.5000) resolutions are 480x320, 720x480, 960x640, 1152x768, 1440x960
• 8:5 (1.6000) resolutions are 320x200, 1280x800, 1440x900, 1680x1050, 1920x1200, 2560x1600
• 5:3 (1.6667) resolutions are 800x480 and 1280x768
• 16:9 (1.7778) resolutions: 1280x720 and 1920x1080

As you can see, if you use the equivalent of FOV 90 on eg 1680x1050 you get a FOV of 100 with no visual distortion. That's what widescreen gives you!

Some other resolutions: